This invention relates generally to power tools and more particularly to devices for retaining sockets and the like on the output drive shaft of such tools.
Because of the multiplicity of fastening operations and other tool applications, it is desirable to have interchangeable bits, sockets, or other tools to be driven by power tools or other speed drives. For example, in the case of sockets for driving fasteners, literally dozens of sockets of various sizes may be used with the same drive.
There are several different types of drive shafts, but one of the most common is the square drive which has become an industry standard for use on hand held power tools.
The requirements for such a drive shaft are that it allow easy installation and removal of sockets and other tool bits while providing positive retention of such tools during operation. Several retaining devices, having varying degrees of complexity, are currently available. One such device is the common spring loaded pin or ball which is captured in and protrudes laterally from the output shaft of the tool and nests in a groove, hole, or other detent provision inside the socket. This permits installation and removal of the socket by a straight pushing or pulling action to overcome the spring load.
Another retention provision is the so-called "through hole" type. In this case, the output shaft has a lateral hole drilled completely through its drive end. Sockets for us with the through hole type retainer have appropriately placed holes to align with that of the drive shaft. A socket is placed on the shaft, and a pin is inserted through the socket and the drive shaft holes. The pin is held in place by an elastic ring which nests in a circumferential groove on the outside of the socket over the retaining pin holes.
Use of sockets made for the one retention system on a tool having an output shaft with the other retention system is, at best, difficult and, at worst, impossible. This lack of interchangeability creates obvious economic disadvantages no the least of which is the requirement for maintaining duplicate sets of sockets and bits along with duplicate power tools.
The foregoing illustrates limitations known to exist in present retaining pin systems. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.